A generous offering.
Turns out, this is a promotional sweepstakes tied in with Feeding Frenzy 2, a casual Xbox Live Arcade game from your friends at PopCap. The grand prize is a six-night trip for two to Waikiki Beach in Honolulu, which PopCap is sponsoring. You can hit the official site if you want to enter.
Hopefully nobody is missing the economic irony here. Rogue Squadron maker Factor 5 can't pay its employees, and oldschool arcade giant Midway is mere weeks away from bankruptcy; meanwhile, the empire built on such low-impact favorites as Peggle and Zuma is sending you on tropical vacations. If you needed yet more proof the market has shifted toward casual players, look no further.
I see what you did there, Brad.
I'd love to go to Hawaii, but like almost all contests on the xblm, it's US-only.